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Category:LICENSEE EVENT REPORT (SEE ALSO AO
MONTHYEARML20029E1891994-05-13013 May 1994 LER 94-007-00:on 940418,meter Lead Inadvertently Touched Adjacent Terminal Resulting in RCIC Inboard Steam Valve Closure.Caused by Personnel Error.Corrective Action:Meetings Were Held & self-assessments in progress.W/940513 Ltr ML20029D6171994-04-29029 April 1994 LER 94-005-01:on 940330,potential Use of Less Conservative pressure-temp Limit Curves Identified.Caused by Inadequate Procedural Guidance.Corrective Actions:Adverse Condition Rept initiated.W/940429 Ltr ML20029D0051994-04-28028 April 1994 LER 94-005-00:on 940404,two PCIS Group 6 RIP Valves Had Dual Open/Closed (Red/Green) Indications.Cause Was Personnel Error.Corrective Action:Individuals Involved Counseled on event.W/940428 Ltr ML20029C8491994-04-25025 April 1994 LER 94-004-00:on 940329,penetration Leakage in Excess of TS Allowable Limit During Local Leak Rate Testing Identified. Troubleshooting & Analysis of Failure Mechanism in Progress. Suppl to Rept Will Be submitted.W/940425 Ltr ML20046B5601993-07-30030 July 1993 LER 92-004-01:on 920730,RWCU Sys Isolated During Substation E7 de-energization Due to Personnel Error.Preparation of Project Plan for Development of Electrical Load List Using Plant Staff Resources underway.W/930730 Ltr ML20045G5821993-07-0808 July 1993 LER 93-003-00:on 930608,RPS MG a Tripped,Resulting in Successful ESF Actuations & Isolations Due to Defective Procedure.Voltage Adjust Potentiometer for MG a Voltage Regulator Replaced on 930617.W/930708 Ltr ML20045F5201993-07-0202 July 1993 LER 93-010-00:on 930604,hourly Fire Watch TS Surveillance Missed During Radiography Due to HP & Operations Failed to Establish Other Means of Communication W/Radiographers. W/930702 Ltr ML20045D6371993-06-30030 June 1993 LER 93-005-01:on 930214,testing of SBGT Showed That Unthrottled Flow of Single Train Would Exceed TS Rated Flow Limit of 3,330 Cfm.Caused by Design Deficiency.Existing SBGT Heaters Upgraded & Rewired ML20045D7601993-06-30030 June 1993 LER 93-008-01:on 930313,spurious ESF Actuations Occurred Due to on-site Electrical Distribution Sys Voltage Depressions. Design of cross-over Points of Transmission Lines Emanating from Plant Being reviewed.W/930624 Ltr ML20045D1531993-06-21021 June 1993 LER-93-007-00:on 930522,discovered That MSL D High Flow Trip Unit Failed Downscale Due to Personnel Error.Appropriate Operations Personnel counselled.W/930617 Ltr ML20045D5881993-06-17017 June 1993 LER 93-006-00:on 930521,HCU 06-31 Declared Inoperable When CRD Accumulator Low Pressure/High Level Alarm Received in Cr.Hcu 02-23 Inoperable at Time.Hcu 02-23 Restored to Svc & Excess Water Drained from HCU 06-31.W/930617 Ltr ML20044E5241993-05-24024 May 1993 LER 93-007-00:on 930424,discovered That Sampling of Rv Coolant Conductivity Not Performed Due to Misinterpretation of RCS Chemistry Ts.Chemistry Sampling of Rv Coolant re-established.W/930521 Ltr ML20044E5411993-05-20020 May 1993 LER 93-009-00:on 930421,found That Design of SBGTS Would Allow Operation That Would Result in Sys Damage If Containment Venting in Progress & Experience Loca.Operating Procedures 1-OP-10 & 1-OP-24 revised.W/930520 Ltr ML20044B6761993-02-22022 February 1993 LER 93-001-00:on 930121,determined That Containment Atmospheric Control Airborne Particulate & Gaseous Radioactivity Monitors Not Seismically Qualified.Suppl to Rept Will Be submitted.W/930227 Ltr ML20029A9111991-02-25025 February 1991 LER 91-001-00:on 910125,reactor Scram Occurred During Calibr of Feedwater Computer Point.Caused by Incorrect Procedure in Summary Sheet.Maint Procedures Reviewed & revised.W/910225 Ltr ML20028H7141991-01-24024 January 1991 LER 90-019-00:on 901226,isolation Signal Caused Reactor Water Cleanup Inlet Inboard Isolation Valve to Automatically Close.Caused by de-energized HPCI Isolation Relay.Riley Scam Temp Switch Units Will Be replaced.W/910124 Ltr ML20024F7461990-12-13013 December 1990 LER 90-020-00:on 901117,primary & Secondary Containment Isolation Signals Received & Standby Gas Treatment Sys auto- Started.Caused by Scan Overload on Microprocessor.Updated Microprocessor Will Be obtained.W/901213 Ltr ML20028H0421990-09-28028 September 1990 LER 90-012-00:on 900830,Unit 2 Reactor Scram Occurred During Reactor Startup.Investigation Continuing.Level Recovered W/O Need for Safety Sys Injection & Unit Designed for Level Transient from Full power.W/900928 Ltr ML20028H0431990-09-28028 September 1990 LER 90-011-00:on 900830,RWCU Sys G31 Received Leak Hi & RWCU Leak Hi Hi Annunciators Although Actual Leak Had Not Occurred.Caused by Air in Instrument 2-G31-FT-N012 Sensing Lines.Investigation to Be conducted.W/900928 Ltr ML20043G0981990-06-15015 June 1990 LER 88-001-06:on 880102,manual Reactor Protection Sys Trip Initiated Due to Decreasing Condenser Vacuum.Cause Still Undetermined.Vendor Insp Revealed Presence of Oil Base Film in Solenoid Valves.Determination Due by 900801.W/900615 Ltr ML20043G0711990-06-13013 June 1990 LER 90-005-00:on 900514,unplanned Closure of HPCI Isolation Valve Occurred During Maint Surveillance Test.Caused by Technician Placing RCIC Instead of HPCI Test Switch to Test Position.Personnel Counseled & trained.W/900613 Ltr ML20043F6291990-06-11011 June 1990 LER 90-008-00:on 900514,HPCI Sys Rendered Inoperable When Control Power Lost to Min Flow Bypass Valve to Suppression Pool.Probably Caused by Design Problem W/Ge Model CR2940 Sockets.Light Bulb & Fuse replaced.W/900611 Ltr ML20043F6181990-06-0808 June 1990 LER 90-007-00:on 900511,identified That Damper Would Fail to Close on Loss of Power to Solenoid Valve & on 900526,damper Found Approx 30 Degrees Open.Caused by Failure of Design to Include Fail Safe Damper.Damper modified.W/900608 Ltr ML20043C9001990-06-0101 June 1990 LER 90-009-00:on 900507,determined That Tech Spec 4.6.1.1 Requirements Not Met After Performing Monthly Periodic Test 2.2.4a.Caused by Inadequate Procedure.Recommended Procedure Revs to Prevent Recurrence Being evaluated.W/900601 Ltr ML20043B7971990-05-25025 May 1990 LER 90-006-00:on 900426,hydraulic Perturbation Occurred on Variable Leg of Instrumentation Used to Sense Reactor Water Level,Causing Isolation of RWCU Sys & Initiation of Standby Gas Treatment Sys.Diaphragm Assembly recalibr.W/900525 Ltr ML20043A6121990-05-11011 May 1990 LER 90-003-01:on 900312,full Group 1 Isolation Signal Received,Resulting in Automatic Closure of Msivs.Caused by Personnel Failing to Follow Procedures.Personnel Counseled & Procedure Separated Into Two tests.W/900511 Ltr ML20012E0581990-03-23023 March 1990 LER 90-002-00:on 900224,Group I Isolation Occurred When Undervoltage Relay Replaced.Caused by Lack of Recognition of Significance of Having Turbine Reset While Performing Electro Hydraulic Control evolutions.W/900323 Ltr ML20012B8071990-03-0909 March 1990 LER 90-001-00:on 900210,determined That Core Spray Loops a & B Inoperable Due to Missed Surveillance.Cause Not Stated. Investigation continuing.W/900309 Ltr ML20012A1671990-03-0202 March 1990 LER 89-013-01:on 890909,HPCI Turbine Auxiliary Oil Pump Developed Shaft Seal Leak of Approx 1 Gpm.Caused by Failure of Shaft Seal.Root Cause of Seal Failure Initiated.Pump Seal replaced.W/900302 Ltr ML20011F5541990-02-22022 February 1990 LER 90-002-00:on 900127,common Control Bldg HVAC Sys Isolated & Transferred to Recirculation Mode as Result of Spurious Actuation of Chlorine Detector.Sensor Connection checked.W/900222 Ltr ML20006E7751990-02-19019 February 1990 LER 88-001-05:on 880102,manual Reactor Protection Sys Trip Initiated Due to Decreasing Condenser Vacuum.Caused by Numerous Leaks on Main Turbine & Main Steam Reheat Interconnecting Piping.Seating Matl installed.W/900219 Ltr ML20011F5311990-02-16016 February 1990 LER 89-026-01:on 891210,common Emergency Bus E3 Unexpectedly Deenergized,Causing Standby Gas Treatment Sys Isolation & Reactor Scram Signal.Caused by Procedural Inadequacy.Isolation Reset & Power restored.W/900216 Ltr ML20006E3681990-02-0909 February 1990 LER 88-006-02:on 880219,numerous Bolt Head Failures of 5/16- Inch X 1/2-inch Silicon Bronze Carriage Bolts Noted in Bus/ Bar Connections of Electrical Switchboards.Caused by Igscc. Bolts Replaced.Reportable Per Part 21.W/900209 Ltr ML20011E1601990-02-0101 February 1990 LER 90-001-00:on 900102,RCIC Removed from Svc & HPCI Rendered Inoperable,Placing Unit in Tech Spec 3.0.3.Caused by Personnel Error.Individual Counseled & Standing Instruction 90-003 issued.W/900201 Ltr ML19354E5651990-01-24024 January 1990 LER 89-021-00:on 891225,electrical Protection Assembly Output Breakers Associated W/Bus a of Reactor Protection Sys Tripped Open.Cause of Trip Unknown.Voltage & Frequency Output of Motor Generator a monitored.W/900124 Ltr ML19354E5611990-01-19019 January 1990 LER 89-025-00:on 891223,sample Lines for Stack Radiation Monitor Froze,Resulting in Samples Not Indicative of Ongoing Releases.Caused by Lack of Insulation on Lines Exiting Stack.Sample Lines insulated.W/900119 Ltr ML19354D8951990-01-16016 January 1990 LER 89-020-00:on 891217,relay in Reactor Protection Sys B Motor Generator Set Control Panel Burned Out,Resulting in Logic Trip of Bus B & Isolation of Standby Gas Treatment Sys.Caused by Circuit malfunction.W/900116 Ltr ML20005F0501990-01-0404 January 1990 LER 89-026-00:on 891210,loss of E3 Bus While Deenergizing Bus 2D for Scheduled Maint Occurred.Caused by Procedural Inadequacy of Plant Electric Sys Operating Procedures.Unit Reset & Sys Returned to normal.W/900104 Ltr ML20042D3551990-01-0202 January 1990 LER 89-019-00:on 891208,Group 6 Isolation Occurred W/Standby Gas Treatment Sys Auto Start During Performance of MST-SCIS21R.Caused by Inadequate Work Practices.Work Crew Counseled.Calibr Procedures May Be revised.W/900102 Ltr ML20005E3461989-12-27027 December 1989 LER 89-024-00:on 891127,17 Primary Containment Isolation Valves Not Tested Per Tech Spec Surveillance Requirement 4.6.1.1.a.Caused by Failure to Recognize Applicability of Testing.Test Rev completed.W/891227 Ltr ML20011D8411989-12-15015 December 1989 LER 89-009-01:on 890617,manual Reactor Scram Initiated Per NRC Bulletin 88-007 Due to Loss of Recirculation Pumps, Causing Loss of Offsite Power & Containment Isolation. Caused by Personnel Error.Hpci Sys secured.W/891215 Ltr ML20011D2251989-12-14014 December 1989 LER 89-023-00:on 891116,reactor Shutdown When Drywell to Suppression Chamber Vacuum Breaker Opened.Caused by Excessive Vibration & Lack of Proper Space Between Actuator Arm & Piston.Procedures Will Be revised.W/891214 Ltr ML19332E9001989-12-0707 December 1989 LER 89-022-00:on 891110,automatic Isolation of Units 1 & 2 Common Control Bldg HVAC & Emergency Air Filtration Sys Occurred.Cause Not Determined.Detectors auto-reset & Sys Returned to Normal svc.W/891207 Ltr ML19332D5791989-11-27027 November 1989 LER 89-018-00:on 891101,determined That Safety Relief Valves Did Not Actuate within Required +/- 1.0% of Setpoints.Cause Not Determined.Setpoints recertified.W/891127 Ltr ML19332C3861989-11-21021 November 1989 LER 89-021-00:on 891022,inadvertent LOCA Initiation Signal Occurred During Monthly Channel Calibr & Functional Test. Caused by Technician Miscommunication.Involved Technicians counseled.W/891121 Ltr ML19327C2021989-11-14014 November 1989 LER 89-019-01:on 890914,determined That Svc Water Sys May Not Have Met Design Requirements Under worst-case Conditions.Caused by Inadequate Component design.Cross-tie Valves Installed.Also Reported Per Part 21.W/891114 Ltr ML19324C3171989-11-0707 November 1989 LER 89-020-00:on 891011,HPCI F006 Valve Motor Control Ctr Indicating Light Socket Shorted & Blew Control Power Fuse for Valve.Caused by Inward Force Applied to Bulb During Removal.Lamp,Socket & Fuse replaced.W/891107 Ltr ML19324C1041989-11-0606 November 1989 LER 89-017-00:on 891010,low Level Signals Occurred,Causing Group 1 Isolation,Core Spray Initiation Signal & auto-start of Common Emergency Diesel Generators.Caused by Perturbation of Ref Leg.Procedures revised.W/891106 Ltr ML19327B9861989-11-0606 November 1989 LER 89-017-01:on 890624,HPCI Sys,Steam Line Break Delta Pressure High Signal,Channel A,Isolation Occurred.Root Cause Investigation Underway.Work Request/Job Order Initiated Requesting Verification of readings.W/891106 Ltr ML19354D4401989-11-0101 November 1989 LER 89-016-01:on 890614,determined That Some Valves Listed in Table 1 of LER Not Tested Per Tech Specs.Caused by Failure to Establish Proper Procedural Controls.Valve Acceptance Criteria Basis Sheets updated.W/891101 Ltr 1994-05-13
[Table view] Category:RO)
MONTHYEARML20029E1891994-05-13013 May 1994 LER 94-007-00:on 940418,meter Lead Inadvertently Touched Adjacent Terminal Resulting in RCIC Inboard Steam Valve Closure.Caused by Personnel Error.Corrective Action:Meetings Were Held & self-assessments in progress.W/940513 Ltr ML20029D6171994-04-29029 April 1994 LER 94-005-01:on 940330,potential Use of Less Conservative pressure-temp Limit Curves Identified.Caused by Inadequate Procedural Guidance.Corrective Actions:Adverse Condition Rept initiated.W/940429 Ltr ML20029D0051994-04-28028 April 1994 LER 94-005-00:on 940404,two PCIS Group 6 RIP Valves Had Dual Open/Closed (Red/Green) Indications.Cause Was Personnel Error.Corrective Action:Individuals Involved Counseled on event.W/940428 Ltr ML20029C8491994-04-25025 April 1994 LER 94-004-00:on 940329,penetration Leakage in Excess of TS Allowable Limit During Local Leak Rate Testing Identified. Troubleshooting & Analysis of Failure Mechanism in Progress. Suppl to Rept Will Be submitted.W/940425 Ltr ML20046B5601993-07-30030 July 1993 LER 92-004-01:on 920730,RWCU Sys Isolated During Substation E7 de-energization Due to Personnel Error.Preparation of Project Plan for Development of Electrical Load List Using Plant Staff Resources underway.W/930730 Ltr ML20045G5821993-07-0808 July 1993 LER 93-003-00:on 930608,RPS MG a Tripped,Resulting in Successful ESF Actuations & Isolations Due to Defective Procedure.Voltage Adjust Potentiometer for MG a Voltage Regulator Replaced on 930617.W/930708 Ltr ML20045F5201993-07-0202 July 1993 LER 93-010-00:on 930604,hourly Fire Watch TS Surveillance Missed During Radiography Due to HP & Operations Failed to Establish Other Means of Communication W/Radiographers. W/930702 Ltr ML20045D6371993-06-30030 June 1993 LER 93-005-01:on 930214,testing of SBGT Showed That Unthrottled Flow of Single Train Would Exceed TS Rated Flow Limit of 3,330 Cfm.Caused by Design Deficiency.Existing SBGT Heaters Upgraded & Rewired ML20045D7601993-06-30030 June 1993 LER 93-008-01:on 930313,spurious ESF Actuations Occurred Due to on-site Electrical Distribution Sys Voltage Depressions. Design of cross-over Points of Transmission Lines Emanating from Plant Being reviewed.W/930624 Ltr ML20045D1531993-06-21021 June 1993 LER-93-007-00:on 930522,discovered That MSL D High Flow Trip Unit Failed Downscale Due to Personnel Error.Appropriate Operations Personnel counselled.W/930617 Ltr ML20045D5881993-06-17017 June 1993 LER 93-006-00:on 930521,HCU 06-31 Declared Inoperable When CRD Accumulator Low Pressure/High Level Alarm Received in Cr.Hcu 02-23 Inoperable at Time.Hcu 02-23 Restored to Svc & Excess Water Drained from HCU 06-31.W/930617 Ltr ML20044E5241993-05-24024 May 1993 LER 93-007-00:on 930424,discovered That Sampling of Rv Coolant Conductivity Not Performed Due to Misinterpretation of RCS Chemistry Ts.Chemistry Sampling of Rv Coolant re-established.W/930521 Ltr ML20044E5411993-05-20020 May 1993 LER 93-009-00:on 930421,found That Design of SBGTS Would Allow Operation That Would Result in Sys Damage If Containment Venting in Progress & Experience Loca.Operating Procedures 1-OP-10 & 1-OP-24 revised.W/930520 Ltr ML20044B6761993-02-22022 February 1993 LER 93-001-00:on 930121,determined That Containment Atmospheric Control Airborne Particulate & Gaseous Radioactivity Monitors Not Seismically Qualified.Suppl to Rept Will Be submitted.W/930227 Ltr ML20029A9111991-02-25025 February 1991 LER 91-001-00:on 910125,reactor Scram Occurred During Calibr of Feedwater Computer Point.Caused by Incorrect Procedure in Summary Sheet.Maint Procedures Reviewed & revised.W/910225 Ltr ML20028H7141991-01-24024 January 1991 LER 90-019-00:on 901226,isolation Signal Caused Reactor Water Cleanup Inlet Inboard Isolation Valve to Automatically Close.Caused by de-energized HPCI Isolation Relay.Riley Scam Temp Switch Units Will Be replaced.W/910124 Ltr ML20024F7461990-12-13013 December 1990 LER 90-020-00:on 901117,primary & Secondary Containment Isolation Signals Received & Standby Gas Treatment Sys auto- Started.Caused by Scan Overload on Microprocessor.Updated Microprocessor Will Be obtained.W/901213 Ltr ML20028H0421990-09-28028 September 1990 LER 90-012-00:on 900830,Unit 2 Reactor Scram Occurred During Reactor Startup.Investigation Continuing.Level Recovered W/O Need for Safety Sys Injection & Unit Designed for Level Transient from Full power.W/900928 Ltr ML20028H0431990-09-28028 September 1990 LER 90-011-00:on 900830,RWCU Sys G31 Received Leak Hi & RWCU Leak Hi Hi Annunciators Although Actual Leak Had Not Occurred.Caused by Air in Instrument 2-G31-FT-N012 Sensing Lines.Investigation to Be conducted.W/900928 Ltr ML20043G0981990-06-15015 June 1990 LER 88-001-06:on 880102,manual Reactor Protection Sys Trip Initiated Due to Decreasing Condenser Vacuum.Cause Still Undetermined.Vendor Insp Revealed Presence of Oil Base Film in Solenoid Valves.Determination Due by 900801.W/900615 Ltr ML20043G0711990-06-13013 June 1990 LER 90-005-00:on 900514,unplanned Closure of HPCI Isolation Valve Occurred During Maint Surveillance Test.Caused by Technician Placing RCIC Instead of HPCI Test Switch to Test Position.Personnel Counseled & trained.W/900613 Ltr ML20043F6291990-06-11011 June 1990 LER 90-008-00:on 900514,HPCI Sys Rendered Inoperable When Control Power Lost to Min Flow Bypass Valve to Suppression Pool.Probably Caused by Design Problem W/Ge Model CR2940 Sockets.Light Bulb & Fuse replaced.W/900611 Ltr ML20043F6181990-06-0808 June 1990 LER 90-007-00:on 900511,identified That Damper Would Fail to Close on Loss of Power to Solenoid Valve & on 900526,damper Found Approx 30 Degrees Open.Caused by Failure of Design to Include Fail Safe Damper.Damper modified.W/900608 Ltr ML20043C9001990-06-0101 June 1990 LER 90-009-00:on 900507,determined That Tech Spec 4.6.1.1 Requirements Not Met After Performing Monthly Periodic Test 2.2.4a.Caused by Inadequate Procedure.Recommended Procedure Revs to Prevent Recurrence Being evaluated.W/900601 Ltr ML20043B7971990-05-25025 May 1990 LER 90-006-00:on 900426,hydraulic Perturbation Occurred on Variable Leg of Instrumentation Used to Sense Reactor Water Level,Causing Isolation of RWCU Sys & Initiation of Standby Gas Treatment Sys.Diaphragm Assembly recalibr.W/900525 Ltr ML20043A6121990-05-11011 May 1990 LER 90-003-01:on 900312,full Group 1 Isolation Signal Received,Resulting in Automatic Closure of Msivs.Caused by Personnel Failing to Follow Procedures.Personnel Counseled & Procedure Separated Into Two tests.W/900511 Ltr ML20012E0581990-03-23023 March 1990 LER 90-002-00:on 900224,Group I Isolation Occurred When Undervoltage Relay Replaced.Caused by Lack of Recognition of Significance of Having Turbine Reset While Performing Electro Hydraulic Control evolutions.W/900323 Ltr ML20012B8071990-03-0909 March 1990 LER 90-001-00:on 900210,determined That Core Spray Loops a & B Inoperable Due to Missed Surveillance.Cause Not Stated. Investigation continuing.W/900309 Ltr ML20012A1671990-03-0202 March 1990 LER 89-013-01:on 890909,HPCI Turbine Auxiliary Oil Pump Developed Shaft Seal Leak of Approx 1 Gpm.Caused by Failure of Shaft Seal.Root Cause of Seal Failure Initiated.Pump Seal replaced.W/900302 Ltr ML20011F5541990-02-22022 February 1990 LER 90-002-00:on 900127,common Control Bldg HVAC Sys Isolated & Transferred to Recirculation Mode as Result of Spurious Actuation of Chlorine Detector.Sensor Connection checked.W/900222 Ltr ML20006E7751990-02-19019 February 1990 LER 88-001-05:on 880102,manual Reactor Protection Sys Trip Initiated Due to Decreasing Condenser Vacuum.Caused by Numerous Leaks on Main Turbine & Main Steam Reheat Interconnecting Piping.Seating Matl installed.W/900219 Ltr ML20011F5311990-02-16016 February 1990 LER 89-026-01:on 891210,common Emergency Bus E3 Unexpectedly Deenergized,Causing Standby Gas Treatment Sys Isolation & Reactor Scram Signal.Caused by Procedural Inadequacy.Isolation Reset & Power restored.W/900216 Ltr ML20006E3681990-02-0909 February 1990 LER 88-006-02:on 880219,numerous Bolt Head Failures of 5/16- Inch X 1/2-inch Silicon Bronze Carriage Bolts Noted in Bus/ Bar Connections of Electrical Switchboards.Caused by Igscc. Bolts Replaced.Reportable Per Part 21.W/900209 Ltr ML20011E1601990-02-0101 February 1990 LER 90-001-00:on 900102,RCIC Removed from Svc & HPCI Rendered Inoperable,Placing Unit in Tech Spec 3.0.3.Caused by Personnel Error.Individual Counseled & Standing Instruction 90-003 issued.W/900201 Ltr ML19354E5651990-01-24024 January 1990 LER 89-021-00:on 891225,electrical Protection Assembly Output Breakers Associated W/Bus a of Reactor Protection Sys Tripped Open.Cause of Trip Unknown.Voltage & Frequency Output of Motor Generator a monitored.W/900124 Ltr ML19354E5611990-01-19019 January 1990 LER 89-025-00:on 891223,sample Lines for Stack Radiation Monitor Froze,Resulting in Samples Not Indicative of Ongoing Releases.Caused by Lack of Insulation on Lines Exiting Stack.Sample Lines insulated.W/900119 Ltr ML19354D8951990-01-16016 January 1990 LER 89-020-00:on 891217,relay in Reactor Protection Sys B Motor Generator Set Control Panel Burned Out,Resulting in Logic Trip of Bus B & Isolation of Standby Gas Treatment Sys.Caused by Circuit malfunction.W/900116 Ltr ML20005F0501990-01-0404 January 1990 LER 89-026-00:on 891210,loss of E3 Bus While Deenergizing Bus 2D for Scheduled Maint Occurred.Caused by Procedural Inadequacy of Plant Electric Sys Operating Procedures.Unit Reset & Sys Returned to normal.W/900104 Ltr ML20042D3551990-01-0202 January 1990 LER 89-019-00:on 891208,Group 6 Isolation Occurred W/Standby Gas Treatment Sys Auto Start During Performance of MST-SCIS21R.Caused by Inadequate Work Practices.Work Crew Counseled.Calibr Procedures May Be revised.W/900102 Ltr ML20005E3461989-12-27027 December 1989 LER 89-024-00:on 891127,17 Primary Containment Isolation Valves Not Tested Per Tech Spec Surveillance Requirement 4.6.1.1.a.Caused by Failure to Recognize Applicability of Testing.Test Rev completed.W/891227 Ltr ML20011D8411989-12-15015 December 1989 LER 89-009-01:on 890617,manual Reactor Scram Initiated Per NRC Bulletin 88-007 Due to Loss of Recirculation Pumps, Causing Loss of Offsite Power & Containment Isolation. Caused by Personnel Error.Hpci Sys secured.W/891215 Ltr ML20011D2251989-12-14014 December 1989 LER 89-023-00:on 891116,reactor Shutdown When Drywell to Suppression Chamber Vacuum Breaker Opened.Caused by Excessive Vibration & Lack of Proper Space Between Actuator Arm & Piston.Procedures Will Be revised.W/891214 Ltr ML19332E9001989-12-0707 December 1989 LER 89-022-00:on 891110,automatic Isolation of Units 1 & 2 Common Control Bldg HVAC & Emergency Air Filtration Sys Occurred.Cause Not Determined.Detectors auto-reset & Sys Returned to Normal svc.W/891207 Ltr ML19332D5791989-11-27027 November 1989 LER 89-018-00:on 891101,determined That Safety Relief Valves Did Not Actuate within Required +/- 1.0% of Setpoints.Cause Not Determined.Setpoints recertified.W/891127 Ltr ML19332C3861989-11-21021 November 1989 LER 89-021-00:on 891022,inadvertent LOCA Initiation Signal Occurred During Monthly Channel Calibr & Functional Test. Caused by Technician Miscommunication.Involved Technicians counseled.W/891121 Ltr ML19327C2021989-11-14014 November 1989 LER 89-019-01:on 890914,determined That Svc Water Sys May Not Have Met Design Requirements Under worst-case Conditions.Caused by Inadequate Component design.Cross-tie Valves Installed.Also Reported Per Part 21.W/891114 Ltr ML19324C3171989-11-0707 November 1989 LER 89-020-00:on 891011,HPCI F006 Valve Motor Control Ctr Indicating Light Socket Shorted & Blew Control Power Fuse for Valve.Caused by Inward Force Applied to Bulb During Removal.Lamp,Socket & Fuse replaced.W/891107 Ltr ML19324C1041989-11-0606 November 1989 LER 89-017-00:on 891010,low Level Signals Occurred,Causing Group 1 Isolation,Core Spray Initiation Signal & auto-start of Common Emergency Diesel Generators.Caused by Perturbation of Ref Leg.Procedures revised.W/891106 Ltr ML19327B9861989-11-0606 November 1989 LER 89-017-01:on 890624,HPCI Sys,Steam Line Break Delta Pressure High Signal,Channel A,Isolation Occurred.Root Cause Investigation Underway.Work Request/Job Order Initiated Requesting Verification of readings.W/891106 Ltr ML19354D4401989-11-0101 November 1989 LER 89-016-01:on 890614,determined That Some Valves Listed in Table 1 of LER Not Tested Per Tech Specs.Caused by Failure to Establish Proper Procedural Controls.Valve Acceptance Criteria Basis Sheets updated.W/891101 Ltr 1994-05-13
[Table view] Category:TEXT-SAFETY REPORT
MONTHYEARML20217N3271999-10-21021 October 1999 Part 21 Rept Re non-linear Oxygen Readings with Two (2) Model 225 CMA-X Containment Monitoring Sys at Bsep.Caused by High Gain Produced by 10K Resistor Across Second Stage Amplifier.Engineering Drawings Will Be Revised BSEP-99-0168, Monthly Operating Repts for Sept 1999 for Bsep,Units 1 & 2. with1999-09-30030 September 1999 Monthly Operating Repts for Sept 1999 for Bsep,Units 1 & 2. with ML20212D0431999-08-31031 August 1999 Monthly Operating Repts for Aug 1999 for Brunswick Steam Electric Plant,Units 1 & 2 ML20210P9441999-08-10010 August 1999 Safety Evaluation Accepting Licensee Assessment of Impact on Operation of Plant,Unit 1,with Crack Indications of 2.11, 6.36 & 1.74 Inches in Three Separate Jet Pump Risers ML20210P9181999-08-10010 August 1999 Safety Evaluation Authorizing Request for Reliefs CIP-01,02, 06,07,08,09,10 & 11 (with Certain Exceptions) & 12-18,for Second 10-year ISI Interval.Request CIP-04 & 05 Would Result in hardship,CIP-03 Not Required & CIP-11 Denied in Part ML20210N2341999-08-0505 August 1999 SER Accepting Response to NRC GL 87-02, Verification of Seismic Adequacy of Mechanical & Electrical Equipment in Operating Reactors,Unresolved Safety Issues (USI) A-46 ML20210R1191999-07-31031 July 1999 Monthly Operating Repts for July 1999 for Bsep,Units 1 & 2 ML20210R1311999-06-30030 June 1999 Revised Monthly Operating Rept for June 1999 for Bsep,Unit 2 BSEP-99-0118, Monthly Operating Repts for June 1999 for Bsep,Units 1 & 2. with1999-06-30030 June 1999 Monthly Operating Repts for June 1999 for Bsep,Units 1 & 2. with BSEP-99-0095, Monthly Operating Repts for May 1999 for Brunswick Steam Electric Plant,Units 1 & 2.With1999-05-31031 May 1999 Monthly Operating Repts for May 1999 for Brunswick Steam Electric Plant,Units 1 & 2.With ML20210M8581999-05-14014 May 1999 B214R1 RPV Hydrotest Bolted Connection Corrective Action Evaluation, Rev 0 ML20211L3711999-05-10010 May 1999 Rev 0 to ESR 98-00333, Unit 2 Invessel Feedwater Sparger Evaluation ML20206G1871999-05-0404 May 1999 Safety Evaluation Approving Third 10-year ISI Program Requests for Relief (RR) RR-08,RR-15 & RR-17 BSEP-99-0075, Monthly Operating Repts for Apr 1999 for Brunswick Steam Electric Plant,Unit 1 & 2.With1999-04-30030 April 1999 Monthly Operating Repts for Apr 1999 for Brunswick Steam Electric Plant,Unit 1 & 2.With ML20206N1791999-04-23023 April 1999 Rev 0 to 2B21-0554, Brunswick Unit 2,Cycle 14 Colr BSEP-99-0059, Monthly Operating Repts for Mar 1999 for Brunswick Steam Electric Plant,Units 1 & 2.With1999-03-31031 March 1999 Monthly Operating Repts for Mar 1999 for Brunswick Steam Electric Plant,Units 1 & 2.With ML20205F9031999-03-30030 March 1999 Safety Evaluation Supporting Proposed Rev to BSEP RERP to Licenses DPR-62 & DPR-71,respectively ML20206N1831999-02-28028 February 1999 Rev 0 to Suppl Reload Licensing Rept for Bsep,Unit 2 Reload 13 Cycle 14 BSEP-99-0043, Monthly Operating Repts for Feb 1999 for Brunswick Steam Electric Plant,Units 1 & 2.With1999-02-28028 February 1999 Monthly Operating Repts for Feb 1999 for Brunswick Steam Electric Plant,Units 1 & 2.With ML20203D7061999-02-0909 February 1999 SER Accepting Proposed Alternatives Contained in Relief Requests PRR-04,VRR-04,VRR-13,PRR-01,PRR-03,VRR-01.VRR-07, VRR-08 & VRR-09 Denied BSEP-99-0005, Monthly Operating Repts for Dec 1998 for Brunswick Steam Electric Plant,Units 1 & 2.With1998-12-31031 December 1998 Monthly Operating Repts for Dec 1998 for Brunswick Steam Electric Plant,Units 1 & 2.With BSEP-98-0231, Monthly Operating Repts for Nov 1998 for Brunswick Steam Electric Plant,Units 1 & 2.With1998-11-30030 November 1998 Monthly Operating Repts for Nov 1998 for Brunswick Steam Electric Plant,Units 1 & 2.With BSEP-98-0218, Monthly Operating Repts for Oct 1998 for Bsep,Units 1 & 2. with1998-10-31031 October 1998 Monthly Operating Repts for Oct 1998 for Bsep,Units 1 & 2. with BSEP-98-0210, Special Rept:On 980824,temp Element 2-CAC-TE-1258-22 Failed. Cause of Failed Temp Element Cannot Be Conclusively Determined.Temp Element Will Be Replaced & Cable Connections Repaired1998-10-30030 October 1998 Special Rept:On 980824,temp Element 2-CAC-TE-1258-22 Failed. Cause of Failed Temp Element Cannot Be Conclusively Determined.Temp Element Will Be Replaced & Cable Connections Repaired ML20154P8151998-10-16016 October 1998 SER Accepting Revised Safety Analysis of Operational Transient of 920117,for Plant,Unit 1 ML20154P8591998-10-16016 October 1998 SER Accepting Equivalent Margins Analysis for N-16A/B Instrument Nozzles for Plant,Units 1 & 2 BSEP-98-0202, Monthly Operating Repts for Sept 1998 for Brunswick Steam Electric Plant,Units 1 & 2.With1998-09-30030 September 1998 Monthly Operating Repts for Sept 1998 for Brunswick Steam Electric Plant,Units 1 & 2.With ML20151Y6211998-09-14014 September 1998 BSEP Rept Describing Changes,Tests & Experiments, for Bsep,Units 1 & 2 ML20151Y6371998-09-14014 September 1998 Changes to QA Program, for Bsep,Units 1 & 2 BSEP-98-0185, Monthly Operating Repts for Aug 1998 for Brunswick Steam Electric Plant,Units 1 & 2.With1998-08-31031 August 1998 Monthly Operating Repts for Aug 1998 for Brunswick Steam Electric Plant,Units 1 & 2.With ML20151T5021998-08-0505 August 1998 Project Implementation Plan, Ngg Yr 2000 Readiness Program, Rev 2 BSEP-98-0164, Monthly Operating Repts for July 1998 for BSEP Units 1 & 21998-07-31031 July 1998 Monthly Operating Repts for July 1998 for BSEP Units 1 & 2 ML20236T1961998-07-0101 July 1998 Rev 1 to 2B21-0088, Brunswick Unit 2,Cycle 13 Colr ML20236T1921998-07-0101 July 1998 Rev 1 to 1B21-0537, Brunswick Unit 1,Cycle 12 Colr BSEP-98-0142, Monthly Operating Repts for June 1998 for BSEP Units 1 & 21998-06-30030 June 1998 Monthly Operating Repts for June 1998 for BSEP Units 1 & 2 ML20236T1971998-06-30030 June 1998 Rev 2 to 24A5412, Supplemental Reload Licensing Rept for Brunswick Steam Electric Plant Unit 2 Reload 12 Cycle 13 ML20249B9691998-06-11011 June 1998 Rev 1 to VC44.F02, Brunswick Steam Electric Plant,Units 1 & 2,ECCS Suction Strainers Replacement Project,Nrc Bulletin 96-003 Final Rept BSEP-98-0129, Monthly Operating Repts for May 1998 for Bsep,Units 1 & 21998-05-31031 May 1998 Monthly Operating Repts for May 1998 for Bsep,Units 1 & 2 ML20151S9041998-05-31031 May 1998 Revised Pages to Monthly Operating Rept for May 1998 for Brunswick Steam Electric Plant,Unit 1 BSEP-98-0104, Monthly Operating Repts for Apr 1998 for Brunswick Steam Electric Plant,Units 1 & 21998-04-30030 April 1998 Monthly Operating Repts for Apr 1998 for Brunswick Steam Electric Plant,Units 1 & 2 ML20151S8991998-04-30030 April 1998 Revised Pages to Monthly Operating Rept for Apr 1998 for Brunswick Steam Electric Plant,Unit 1 ML20247N7501998-04-30030 April 1998 Rev 0 to BSEP Unit 1,Cycle 12 Colr ML20247N7721998-04-30030 April 1998 Rev 0 to J1103244SRLR, Supplemental Reload Licensing Rept for BSEP Unit 1,Reload 11,Cycle 12 ML20217K8461998-04-24024 April 1998 Safety Evaluation Approving Proposed Use of Code Case N-535 at Brunswick Unit 1 During Second 10-yr Interval,Pursuant to 10CFR50.55a(a)(3)(i).Authorizes Use of Code Case N-535 Until Code Case Included in Future Rev of RG 1.147 ML20217K3941998-04-24024 April 1998 SER Approving Relief Request for Pump Vibration Monitoring, Brunswick Steam Electric Plant,Units 1 & 2 ML20217E6841998-04-23023 April 1998 Safety Evaluation Accepting Code Case N-547, Alternative Exam Requirements for Pressure Retaining Bolting of CRD Housings ML20217E7471998-04-21021 April 1998 Safety Evaluation Accepting Alternative to Insp of Reactor Pressure Vessel Circumferential Welds ML20217B5241998-04-20020 April 1998 SE Accepting Licensee Request for Approval to Use Alternative Exam Requirement for Brunswick,Unit 1,reactor Vessel Stud & Bushing During Second 10-yr ISI Interval Per 10CFR50.55a(a)(3)(ii) BSEP-98-0080, Monthly Operating Repts for Mar 1998 for Bsep,Units 1 & 21998-03-31031 March 1998 Monthly Operating Repts for Mar 1998 for Bsep,Units 1 & 2 ML20216B1041998-03-0404 March 1998 SER Approving Alternative to Insp of Reactor Pressure Vessel Circumferential Welds for Brunswick Steam Electric Plant, Unit 1 1999-09-30
[Table view] |
Text
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. LICENSEE EVENT REPORT Updnte Riport Proviru3 R p3rt Data 3-18 s t
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3oyR$ [dl 0 l 5 l 0 l - l 0 l 3 l 2 l 4 @l 0 l 310 l 4 l 8 l 1 @l 0 l 6 l 0 l 1 l A l1 68 14 75 REPORT DATE 80 lh 7 60 St DOCKET NUM8ER 63 EVENT DATE EVENT OESCRIPT10N AND PROBAB,LE CONSEQUENCES h ,
l o 121 l While performing Periodic Test 19.6.1. Function Test nf Saforv Re19ead acco==4hla I
,o,3, gSnubbers, a failure rate of approximately 20% was observed on snubbers located outsidel
- o,,,;the drywell. After evaluating the modes of failure and the high failure percentage l l c I s 1 [ rate, it was decided to shut down Unit No. 2. The snubber inspection continued and l l o is- 1h l as now been completed. Of the 640 snubbers tested, 130 failed the functional test. l l0l7ll l IoIe I i Technical Specifications 3.7.5, 6.9.1.81 l
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'NI'E *^$E CO sis 8Ciot COMPONENT CODE SL8C O'E S E
[o_L9_l l v l y l@ b@ [3_j h l S l U l P l O ! R l T lh l D lh l Zlh 20 7 8 9 10 11 12 13 18 19
_ SEQUENTI AL OtCURAENCT REPORT R EVISION L EVENT YEAR R EPORT NO. CODE TYPE N O.
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_,21 22 23 24 26 27 28 29 30 31 32 K N AC ON ON PL NT MET wCURS 22 S8 IT PO 9 8. SUPPLI VANL CTLRER lB lgl34 Fl g l5 Alg l 0l 3l 1l dl l Yl@ lYl@ lAl@ lBl2l0l9l@
33 3 [36Al@ 37 40 di 42 o. 43 44 47 CAUSE OESCRIPTION AND CORRECTIVE ACTIONS li j o i {The majority of the snubber failures were caused by worn snubber poepets which occurred g gdue to poppets' low resistance to pipe vibrations. The failed snubbers were rebufle. I ii121 1 retested satisfactorily and reinstalled. A 100% snubber reolacement has been l l g,;3; jscheduled for Unit No. 1 during its current maintenance outage. The Unit No. 2 snubbed i
1 g l valve bodies will be replaced during a future outage. I
, 7 8 9 80
$ $ $*CWER OTHER STATUS i O RY DISCOVERY DESCRIPTION Ii l 5 l l E ]@ l 0l 9 l 5 l@l NA l lBl@l Routine Surveillance l ACTIVITY CO TENr RELEASED OPRELEASE AMOUNT OF ACTIVITY LOCATION OP RELE ASE li l6 dl 9l Z j @ l Zlgl 10 NA l 44 l'
45 NA 80 l
7 11 PERSONNEL EXPOSLRES Nuu8ER TYPE DE SCRIPTION i l i l 7 I l 0 l 0 l 0 l@l Z l@l NA l
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,ERSoNNEL ,Nau'IES
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W VRER DESCRIPTICN NA li 14s 11010
/ 9 l0 l@l12 11 90 I
LOSS OP OR OavaGE TO FACILITV TvPE DEgniorroN libllZl@l 7 s 1, to NA 30 l
is u @ia t ,0N ttuij lWg[8l NA l ll ll llllll llljI i 4 'J tu 68 0 -) 50* 3
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M. J. Pastva, Jr. 919-457-9521 2 PHONE. _,_
s 3 o s o sAif g & Asen "
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1981 UNIT NO. 2 CHOCK SUPPRESSOR TESTING REPORT
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INTRODUCTION In March 1981, Carolina Power & Light's Brunswick Unit No. 2 began , testing hydraulic shock suppressors - snubbers - according to technical specifications.
A total of 640 snubbers were removed from service and functionally tested. Of this number, 130 failed the tests. An additional 80 snubbers were rebuilt for preventative maintenance, raising the total rebuilt to 210. A program was established to inspect and evaluate each snubber that was rebuilt. A large percentage of the rebuilt snubbers were found to be degraded with worn poppets, and deformed poppet retaining springs.
DESCRIPTION Each snubber pulled was functionally tested at least once. If a snubber failed the acceptance criteria, it was categorized as a " failure" and rebuilt, retested satisfactorily, and reinstalled. Those snubbers which passed with low margin were rebuilt, ratested satisfactorily, and reinstalled. These are classified as preventive maintenance rebuilds.
During disassembly all parts were inspected by an engineer or technician. Stan-dard inspection sheets were used for consistent inspections. The snubbers were then rebuilt using ncy parts as necessary and retested. After reinstallation all snubbers were inspected by plant QA personnel for proper installation. -
All test data and inspection sheets were forwarded from the inspection group to the evaluation group to determine from the information available the. reason for the test rejection and the cause of the degradations found during the part inspections. Included in this analysis was a determination if the system's operation had an effect on the function of the snubber to the extent it would cause failure; that is, determine if the snubber is " service sensitive."
An information file was established for each snubber received by the evaluation group. Each snubber was researched to determine which system and line it was
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from, and the function of the line. The location of the snubber was inspected for evidence of either snubber or pipe movement. The testing and maintenance
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history of the snubber was examined for past or recurring problems. Comments
! were also obtained from Operations personnel as to whether the line vibrated during service or had a history of water / steam hammer.
I From the information compiled in the folder, each snubber was first evaluated individually. The results of the part inspections were compared to the reason for test rejection to identify the rejection mode. Next, a determination of service censitivity was made. For this determination, all the information in the folder was weighed together. The determination that a snubber is service
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sensitive was not made unless the majority of the information substantiated such an evaluation. In cases where the snubber appeared to have experienced a l
water / steam hammer situation, the same snubber and adjacent piping on Unit No. I was visually inspected for signs of water hammer. Had a similar situction been identified, the line would have been declared inoperative and the applicable LCO initiated.
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RESULTS_
The results of the evaluation program described above are shown in Tables 1 through 3. .
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DISCUSSION l
Comparing the test data for each snubber and the test criteria, the reason for test rejection for each snubber was identified. See Table 1. Test rejections include both snubbers rebuilt due to failure of the acceptance criteria and g
those rebuilt due to low margin. TI% most prevalent reason was ' low bleed. ' Of ,
the snubbers rebuilt for failure and preventive maintenance, 45*. were rebuilt )
because of low Lleed velocities. The second highest reason for test rejection .i was 'high lockup' which accounted for 17*. of the snubbers rebuilt.
Review of the inspection sheets for each snubber identified ' the degraded-condition of its co=ponents. Snubbers were frequently found degraded in more than one way. For example, a snubber could have worn poppets, and deterioriated !
3 seals. The percentages shown in Table 2, therefore, represents the number of snubbers in which the type of degradation appeared. !
Varying degrees of poppet wear were found in 62*. of all the snubbers evaluated.
This was predictable since the majority of the snubbers were rejected because of *
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low bleed velocities. The worn poppet grooves restrict nuid f1ow thus causing j lower velocities. ,
Evidence of spring capture was found in 367. of the snubbers rebuilt. Spring -f capture was identified either by spring imprints on both the poppet head and valve body seat or damaged poppet retaining springs. The' spring imprints i identified ranged from " slight marks" to " deep gouges. g Worn poppets, spring capture, and piston / cylinder wear (uniform wear of the h piston or cylinder wall) comprise the three major categories in Table 2. These I categories are the possible consequences of service related conditions. Pipe i vibrations cycle the snubber to the extent that the grooves on the poppet head i begin to wear, and the piston wears on the cylinder walls. Continued cycling g causes the retaining springs to fail and/or deform such that the spring can be ,
' captured.' l t
Deteriorated seals, grease in the fluia, and side loading (localized l
- piston / cylinder wear) account for the three remaining major categories. These
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categories are possible cmsequences of improper installation. [
l i By comparing the degradations found for an individual snubber with the reason for test rejection, the rejection mode was establistl ed. This was not always an ,
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easy or clear cut task since more than one degradation could be present. The .
degradations were reviewed and a category was chosen as the primary rejection l mode. For instance, worn poppets can lead to low bleed velocities, spring g' capture can lead to no lockup, piston / cylinder wear or deteriorated seals can lead to either high bleed or high lockup velocities, and side loading can lead I
- to binding. Worn poppets and spring capture were the rejection mode of 27*. and -!
16* of the snubbers rebuilt respectively; which, as stated above, may be attributable to pipe vibrations.
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As seen in Table 3, 41% had inconclusive evidence to determine the rejection mode. Included in this c'ategory would be the 8% that had no visible degradations. The rejections with no apparent degradation could be attributable '
to improper installation of 0-rings, etc., which was not evident after disassembly. ..
The 41% with inconclusive rejection modes are snubbers with degradations' which c.e seemingly unrelated to the reason for test rejection. A worn compression
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poppet does not contribute to' low bleed velocities found during the extension test. Worn poppets don't contribute to high bleed rates. Evidence of spring capture doesn't lead to low bleed rates. The 41% were reviewed, and no trends were observed. There were many different reasons for test rejection, and many different degradations found. However, worn poppets were evident in most of these snubbers.
Piston / cylinder wear, found in 31% of the snubbers rebuilt, appears to be a less sensitive degradation since it was the rejection mode of only'3% of the snubbers rebuilt.
Reviewing the inspection sheets for each snubber with the other information in the file, an evaluation of service sensitivity was made. Individual maintenance histories, line histories , field inspections, and operational comments were taken into account. Of the snubbers rebuilt, 37% were determined to be service sensitive. That is, the operating conditions of the line and/or snubber were found to have signs of vibration or water hammer and the type of degradation -
fot.nd could be caused by these conditions. 3e majority of the service sensitive snubbers were attributed to vibration, with a nominal number due to water hammer.
In addition to physical inspection of the snubbers, fluid samples were obtained and analyzed. The result of this indicated that nominal fluid viscosity for the GESF1154 fluid varied about + 10% from the typical published range of 175-195 anti-stokes at 77*F. An evaluation of the affect of this variation indicated a
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maximum impact of less than 5 ipm on lockup and fluid velocities. Also, since the functional test actually measures the lockup and bleed velocities, the viscosity affect is included in the test evaluation. Samples analyzed outside the nominal range indicated that foreign materiel such as grease accounted for exceptionally high viscosity readings. Enhanced maintenance instructions will preclude future problems in this area.
CONCLUSIONS In our review of the evaluations, the primary degradation and rejection mode was worn poppets. This is attributable to the poppets' low resistance to pipe vibrations. Replacing the valve bodies with a new, more vibration resistant one
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should lessen this anomaly. The secondary category of spring capture will also be lessened by replacing the valve bodies. A 100% replacement is scheduled for
- Unit No. I during the current outage. The valve body replacement is scheduled at a future outage for Unit No. 2.
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The remaining degradations are attributable to improper installation practices.
To prevent this occurrence in the future, the maintenance procedures have been revised with additional emphasis in areas found to be deficient suel, as increasing the torque value on the jam nut. Each snubber will be rebuilt and inspected during the service life of the snubber. Sufficient QA surveillance-to ensure proper installation quality will also be mainta'ined.
Snubbers - failing the functional tests -in the future will be rebuilt and the parts inspected. Particular emphasis will be given to identifying degradations; namely poppet wear, spring capture, and piston / cylinder wear; and noticing new trends. Engineering evaluations will be made as necessary.
In addition, the information below is provided in response to specific questions which have been asked by NRC Region II personnel.
Lockup Criteria
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The maximum lockup velocity criteria of 55 ipm was reviewed for all snubbers on both unirs. Vertical snubbers were uniquely analyzed to assure that this criteria was acceptable. Final results on both units found that no supports ,
would fail under this criteria; however, three supports per unit require upgrading to stay within code allowable stresses. These support modifications have been completed on Unit No. 2 and will be completed prior to startup of Unit
- No. I which is presently in a maintenance outage.
Test History
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Of the 13 Unit No. 2 snubbers that failed in 1979, five failed in 1981.
Additionally, five'of the eight that passed were rebuilt for preventative maintenance.
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- y. - -+--w- *.v =,,-p wr v,- ,--y- - + - e +- *- d - --- -
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% of Total Rebuilt No Lockup 13 ,
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High Lockup 17 , ,
Low Bleed 45 High Bleed 13 Other 12
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Reason for Test Rejection TABLE 1 .
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% of Total Rebuilt
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Worn Poppets 62 Spring Capture 36 ,
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Piston / Cylinder Wear 31 Deteriorated Seals 28 Grease in Fluid 7
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Side Loading 7 None -8 Degradations Found TABLE 2 4
k 1 #
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e p
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,,.m-w.~ . , . , y_-, y gg,-m-g-m----,,.,y-,e,,,.,-,-,,,,,-.-mn-m...g,,. ,,mm,eg,v-e,--g-n- -gw-,,~,+,,.,m,-- + ,-,-r
,,,-...ew--,,.4.gs-, g - - -
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% of Total Rebuilt Worn Poppets 27 Spring Capture 16 Piston / Cylinder Wear 3 Deteriorated Seals 3 .
Grease in Fluid <1
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Side Loading i Inconclusive Evidence 41
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Miscellaneous 8 .
Rejection Mode
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i TABLE 3
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SNUBBER NO. SIZE TYPE OF FAILURE SYSTEM LOCATION 2B21-44SS129 3 High L/U (ext) Nuclear steam vent line 2" Nuclear steam vent line
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2B21-701SS177 3 High L/U & bleed (ext)
- 2B21-51SS105 3 No bleed locked up in ret HSL condensate drain 2"
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2B21-19sS194 10 High L/U (ext) SRV discha: ge line 6" j
i 2B21-6SS240 10 High L/U (ext) B feedwater line 2B21-18SS213 3 Low Bleed (ret) SRV discharge line 2B21-51SS113 3 High bleed (ext) MSL condensate discharge 2"
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2B21-7SS56 3 High L/U (ext) B feedwater line i 2B21-11SS220 10 Low bleed (ret) SRV discharge line 2B21-3SS12 3 No bleed locked up in ret A feedwater line 2B21-12SS312 10 Lc', bleed (ret) SRV discharge 2B21-11SS223 10 Low bleed (ret / ext) SRV discharge
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2B21-2SS4 10 High L/U (ext) A feedwater line
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2B21-34SS296 10 Low bleed (ret) SRV discharge i 2B21-6SS20 10 H!gh biced (ext) high L/U (ext / ret) B feedwater line 2B21-33SS251 20 Low bleed (ret) SRV discharge
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2B21-19sS193 10 Low bleed (ext) SRV discharge i
L/U - Lockup ret - retracted i ext - extended 4
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2B21-59SS330 10 Low bleed (ret / ext) SRV discharge 10" 2B21-5SS17 - 10 Low bleed (ext) B feedwater line
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2B21-58SS276 10 Low bleed (ret) SRV discharge 10" 2B21-12SS308 3 Low bleed (ret / ext) SRV discharge
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2B21-33SS335 10 Low bleed (ret / ext) SRV discharge 2B21-11SS221 , 10 Low bleed (ret) SRV discharge 2821-33SS333 10 Low bleed (ret) SRV discharge 2B21-34SS299 20 Low bleed (ret / ext) SRV discharge 2B21-47SS155 3 High L/U & bleed (ext) Nuclear steam vent line 1"
. 2B21-27SS269 3 Low biced (ret) SRV_ discharge
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2B21-59sS329 10 Low bleed (ret) SRV discharge 10" 2 Ell-90SS277 3 No bleed (ret) RHR head spray 3/4" 2B21-58SS279 10 Low bleed (ret) SRV discharge 10" 2B21-44SS142 3 Low bleed (ret) Nuclear steam vent line 2"
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2B21-20SS757 3 Lo'w bleed (ret) SRV discharge 2B21-27SS267 3 Low bleed (ext / ret) SRV discharge 2B21-llSS222 10 Low bleed (ret) SRV discharge
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2B21-58SS305 10 Low bleed (ret) SRV disch+.3e 10" L/U - Lockup
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ret - retracted ext - extended -
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SNUBBER NO. SIZE TYPE OF PAILURE SYSTEM LOCATION 2B21-26SS201 . 10 Low bleed (ret) SRV discharge 2B21-20SS261 10 Low bleed (ext) SRV discharge
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2B21-2S53 3 Lou bleed (ret) A feedwater 2B21-58SS275 20 Low bleed (ext) SRV discharge 10" i
2B21-58SS277 20 1.ow bleed (ret)
'
2B21-58SS281 20 Leaking fluid SRV discharge 10" 2B21-34SS300 10 Low' bleed (ext / ret) SRV discharge 3B21-19SS317 3 Low bleed (ret) SRV discharge 2B21-6SS26 3 Low bleed (ext)' B feedwater line 2E11-90SS392 3 High L/U & bleed (ext) RHR head spray 3/4"
! 2 Ell-90SS391 3 liigh L/U (ext / ret) RHR head spray 3/4" 2821-12SS310 3 Low bleed (ret) SRV discharge
' 2PSN-A2SS30 3 Low bleed (ret) Main steam line A 10" r
2B21-12SS312 10 Low bleed (ext / ret) SRV discharge 1
2PSN-B3SS47 20 High bleed (ext) Main steam line B 10" 2B21-llSS314 10 Low bleed (ret) SRV discharge
-
4
,
L/U - Lockup ret - retracted
-
ext - extended l
.
O
_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ . - . _ _ _ _ _ _ _ _ _ _ _ _ _ _ ___ __ _ _
__
. .
' SNUBBER NO. SIZE TYPE OF FAILURE SYSTEH LOCATION
,1
'2B21-12SS287 30 liigh L/U (ret) high L/U & bleed (ext) SRV discharge i .
. 'Sil-87SS318 30 liigh L/U (ret) B RilR return
-
2012-16SS11 - 3 liigh bleed (ret) high L/U (ext) CRD return line 1.
, ,
2C12-16SS8 3 liigh L/U & hieed (ext) CRD return line 2012-16SS10 3 liigh bleed (ext) CRD return line
.
i '
2C41-9SS5 3 tilgh L/U (ret) high bleed (ext) SLC pump discharge 1 1/2" 2B21-26SS207 30 Binding (ext) high L/U (ret) ,
SRV discharge
.
No bleed (ret) i E41-4SS51 10 liigh L/U & (ext) IIPCI steam supply 2B41-4SS49 10 liigh L/U & bleed (ext) HPCI steam supply i
2C12-16SSI 3 liigh biced (ext) CRD return line ,
2PSN-B5SS51 3 Low Bleed (ret) Main steam line B 10" i
2B51-4SS66 3 liigh bleed (ext) RCIC steam supply
~
4 2B51-4SS101 3 No biced (ext / ret) RCIC steam supply 2B32-SSB12B 5" No L/U or bleed (ext) '2B reactor rectre, pump
.
L/U - Lockup i ret - retracted ext - extended l
,
.
_ _ _ _ _ _ _ - _ - _ _ _ _ _ _ - _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ - _ _ _ _ _ _ .
- - ..
,
'
.
.
SNUBBER NO. SIZE TYPE OF FAILURE SYSTEM LOCATION
.
2RCC-65SS129 3 No bleed (ext) 2A RCR pump cooling
' '
Nuclear steam vent line
.
,
2B21-44SS131 3 Low bleed (ret)
- .
2RCC-71SS139 3 No bleed (ext) RBCCW to BRCR pump 2RCC-73SS145 3 No bleed (ext) RBCCW to 2C floor drain HX
-
!'
2B21-26SS208 10 Low biced (ret) SRV discharge
'
2B21-3SS231 10 Leaking fluid A feedwater line
' '
2B32-B9B 3 1/4" High bleed (ret) 2B reactor recirc pump i 2B32SSB6 3 1/4" Binding (ext / ret) 2B reactor recirc oump 2E41-2SS106 10 No L/U HPCI pump disch 2E41-2SS104 10 No L/U HPCI pump die:h 2 Ell-91SS575 3 No L/U RHR head spray
'2E21-2SS32 3 Low bleed Core spray pump 2A disch valve bypaas 2SW-103SS121 10 No L/U' SW supply to RHR booster pumps 2E51-42SS82 3 Broken shaft RCIC steam supply 2E51-40SS83 3 No L/U RCIC pump supply
.
-.. -
_ _ _ _ . - _ _ _ . _ _ _ _ - - _ _ _ _ _ _ _ _ - - _ _ . - _ . - - _ - - - _ _ . - _ _ - - . - - - _ - - _ - - - - _ - - - - - - - . .___ - _ _ _ _ _ - - . _._ . . _ _ _ . -- .
.
'
.
SNUBBER NO. SIZE . TYPE OF FAILURE SYSTEM LOCATION
.
2E51-40SS85 3 Binding RCIC pump supply I' 2E11-18SS470 10 No L/U RllR LPCI injection a
2SW-173SSil4 3 Binding SW return line 2E41-6SS32 3 No L/U llPCI steam exhaust 2E41-6SS33 3 Pio L/U
- 2E51-19SSil3 3 No L/U RCIC turbine inlet drain 2 Ell-46SS9 3 ~No bleed RilR pump discharge
'
2E51-40SS84 3 -No L/U RCIC pump supply a
2E41-12SS98 3 No L/U Fuel' pool cooling from RilR 2SW-106SS156 3 No bleed Supply i
2SW-153SS176 3 No L/U SW return line 2 Ell-58SS36 10 No L/U RilR pump B&D discharge 2SW-106SS151 3 Binding Supply to'RBCCW llX 2E41-6SS30 3 Binding IIPCI steam exhaust
'
2RCC-39SS80 3 No L/U RBCCW pump discharge
.
2E51-19SSil4 3 No L/U RCIC turbine inlet drain f
' .
L/U - Lockup ret - retracted ext - extended
.
.
v
___ _---._ __. - . . _ _ _ _ _ _ _ _ _ _ _ _ .- - - - _ _ . _ . - _ .
.
'
.
SNUBBER NO. SIZE TYPE OF FAILURE SYSTEM LOCATION 2E41-44SS86 3 No L/U llPCI vacuua pump to vent 2E51-42SS79' 3 No bleed RCIC steam supply 2E51-41SS95 3 Binding RCIC pump discharge
"
2SW-174Ss70 3 No L/U SW return line
'
.2SW-139SS172 3 No L/U SW RBCCW llX outlet 2E21-6SS42 3 No L/U CS pump di,scharge 2E51-42S377' 3 Binding RCIC steam supply
]
2E11-56SS13 3 No bleed RilR pump A&C discharge 2 Ell-58SS33 No biced RilR pump B&D discharge
) 3 47 2PS-3423 3 No L/U A0G
> ,
2PS-3417 3 No L/U AOC 2PS-3418A 3 No L/U A0G 2PS-3417B 3 No bleed A0G 2 Ell-53SS195 3 No L/U RilR heat exchange relief line 2E11-46SS510 3 No bleed RilR pump discharge
- 2 Ell-71SS174 3 Low bleed RilR drain to.radwaste
.
_. _ ._ -
_ . - . .. . , _ , _ - _ _ . - - _ _ . . . . . . , -. . .. . . . .
'i 4
I SNUBBER NO. SIZE TYPE OF FAILURE SYSTEM LOCATION 2 Ell-47SS328 3 Binding RilR connection & IIPCI steam supply I 2 Ell-128bS355 3 No L/U Cooling for RilR liX 2A 2 Ell-71SS393 3 No L/U RilR drain to radwaste 1 2PS-3418B 3 No L/U A0G i'
2 Ell-68SS448 3 Relief valve lifting RilR return & test line j- 2E11-56SS517 3 No L/U RilR pump A6C discharge
~
, 2 Ell-127SS435 3 No L/U Cooling for RilR llX 2A ,
,
'
9 J
,
d
' '
4 h
!
4 i
1 i
.,
e